Determination of the atomic coordinates of type I complex (Nuclease T') by X-ray diffraction study. Crystallization and determination of the atomic coordinates of type II complex by X-ray Diffraction study. Studies on the interatomic interactions on the basis of the atomic coordinates of type I and type II complexes and the kinetic and thermodynamic parameters involved in the conformations. Studies on the mechanism of the enzymic activity of nuclease on the basis of the atomic coordinates of type I and type II complexes. Search for an enzyme involved in the formation of cytochrome c from apocytochrome c and heme.